Aggressive Salt Research Articles

Attenuation Law of Performance of Concrete Anti-Corrosion Coating under Long-Term Salt Corrosion

In saline soil areas, the concrete piers of concrete bridges experience long-term corrosion, mainly caused by chloride salts due to alternating temperature changes. Waterborne concrete coatings are prone to failure in this aggressive salt environment. Implementing coating protection measures can improve the durability of concrete and enhance the service life of bridges. However, the effectiveness and longevity of coatings need further research. In this paper, three types of waterborne concrete anti-corrosion coatings were applied to analyze the macro and micro surface morphology under wet–dry cycles and long-term immersion conditions. Various indicators such as glossiness, color difference, and adhesion of the coatings were tested during different cyclic periods. The chloride ion distribution characteristics of the buried concrete coatings in saline soil, the macro morphology analysis of chloride ion distribution regions, and the micro morphology changes of the coatings under different corrosion times were also investigated. The results showed that waterborne epoxy coatings (ES), waterborne fluorocarbon coatings (FS), and waterborne acrylic coatings (AS) all gradually failed under long-term salt exposure, with increasing coating porosity, loss of internal fillers, and delamination. The chloride ion content inside the concrete decreased with increasing depth at the same corrosion time, while the chloride ion content at the same depth increased with time. The chloride ion distribution boundary in the cross-section of concrete with coating protection was not significant, while the chloride ion distribution boundary in the cross-section of untreated concrete gradually contracted towards the concrete core with increasing corrosion time. During the corrosion process in saline soil, the coatings underwent three stages: adherence of small saline soil particles, continuous increase in adhered material area, and multiple layers of uneven coverage by saline soil. The failure process of the coatings still required erosive ions to infiltrate the surface through micropores. The predicted lifespans of FS, ES, and AS coatings, obtained through weighted methods, were 2.45 years, 2.48 years, and 2.74 years, respectively, which were close to the actual lifespans observed in salt environments. The developed formulas effectively reflect the corrosion patterns of different resin-based coatings under salt exposure, providing a basis for accurately assessing the corrosion behavior and protective effectiveness of concrete under actual environmental factors.

STUDYING THE INFLUENCE OF NEW COMBINED INHIBITORS ON THE PROCESSES OF CORROSION AND SALT DEPOSITION IN OIL-FIELD EQUIPMENT

Aggressive salts contained in formation waters accelerate the processes of corrosion and salt deposition in oilfield equipment, which leads to unforeseen accidents, contamination of soil and groundwater with harmful substances, as a result of which the ecological balance of the environment is disrupted. Corrosion and scaling that occur during oil production create difficulties during the operation of wells, and, consequently, increase the cost of produced oil.This article covers the results of studies concerning two compositions developed from technical phosphatide - an emulsion obtained by hydration of vegetable oils, as well as sodium hexametaphosphate, ammophos and polypropylene glycol bottoms. When vegetable oils are treated with water and steam (hydration process), the phospholipids contained in the oils combine with water and are released in the form of precipitates called phosphatide emulsions. Such emulsions consist of 45–75 % water, and the rest is phospholipids in the vegetable oil sediment.Technical phosphatides are a group of esters that contain a phosphoric acid residue associated with an amino alcohol. They are natural surfactants and are non-toxic.Preliminary studies have shown that each of the chemical compounds included in the developed reagents has certain inhibitory properties, but when formulated, these compounds provide a synergistic effect.Based on the results of laboratory studies, it was found that at an optimal concentration of reagents of 200 mg/l, the developed compositions provide protection of equipment from corrosion destruction by 94–95 %, and from scaling by 87–88 %. The developed mixed-type inhibitors at optimal concentrations equally effectively inhibit both cathodic and anodic processes on the electrode.The use of these inhibitors leads to the prevention of steel corrosion in the two-phase oil-electrolyte system, as well as to a significant reduction in the rate of scaling.The proposed new compositions can be used in oil wells and in-field transport systems, as well as in reservoir pressure maintenance systems to protect against corrosion and scale deposits.Field tests of the corrosion inhibitor were carried out in deep pumping wells at the Bibieybatneft oil and gas production department. Tests have shown that as a result of using the inhibitor, the protective effect at a concentration of 200 mg/l was 89–90 %, and the effect of salt deposition was 70 %.

Improvement of the performance characteristics, fire resistance, anti-bacterial activity, and aggressive attack of polymer‐impregnated fired clay bricks-fly ash-composite cements

The research addressed the creation of various composite cement mixes by replacing 40 % of OPC with industrial solid wastes, Fly ash (FA), and/or Fired clay bricks (FCB) at different water/powder (w/p) ratios. The composite cement pastes were subjected to polymer-impregnation process, using methyl-methacrylate (MMA) monomer and benzoyl peroxide as an initiator. The physico-mechanical and chemical characteristics of the polymer-impregnated specimens, such as compressive strength, bulk density, total porosity, and polymer load, were examined. The findings showed that, as compared to neat pastes (PF1, PF2, and PF3), the compressive strength (CS) of mixes (PFH1, PFH2, and PFH3) rose considerably after 3 months of hydration by 10.53 %, 12.82 %, and 28.85 %, respectively. Additionally, mix PFH1 with a water/powder (w/p) ratio of 0.35 exhibited the greatest bulk density value (2.215 g/cm3) and the lowest total porosity percentage (12.72 %). Data demonstrated that polymer-impregnation is efficacious to strengthen constructions subjected to high temperatures and aggressive salt attacks. The study additionally revealed that, when thermally treated at 200, 400, and 600 °C, respectively, the CS of PFH1 paste increased by 1.44 %, 1.78 %, and 1.48 % after 14 days of curing, but increased by 10.85 %, 5.20 %, and 7.89 % at curing time of 28 days. Likewise, when CS was compared to that before to polymer-impregnation up to three months, it grew by 48.53 % following immersion in 5%-MgSO4 solutions but increased by 13.49 % after immersion in 5%-MgCl2 solutions.Moreover, the composite with a water/powder ratio of 0.45 demonstrated remarkable anti-bacterial activity against both Gram-negative and Gram-positive bacteria. In conclusion, the study shows that the compressive strength, antibacterial activity, fire resistance, and resistance to aggressive attacks of the composites are all improved by MMA polymer impregnation.

Salt Crystallization on Crazannes Limestone in a Long-Term Storage Environment

This study focuses on the damage caused by salt crystallization and the associated weathering processes in Crazannes limestone during storage. The main objective was to understand the factors contributing to the limestone’s observed flaking and granular disintegration, which cannot be attributed to frequent salt crystallization cycles experienced in outdoor exposure. Porosity and chemical analyses were performed to identify the salt minerals and their distribution within the stone’s microstructure. Chemical analyses revealed the presence of gypsum on the powdery weathered residues and stone surface, while halite was consistently found throughout the samples, with higher concentrations on the surface. The storage of the blocks in a closed room led to moisture evaporation and an increase in relative humidity (RH) ranging from 60% to 75%. Under these conditions, the gypsum crust remained relatively stable. The threshold for halite crystallization decreased to 65% RH in the presence of other salts. Consequently, even slight fluctuations in RH (%) caused by seasonal variations could induce cycles of NaCl crystallization and dissolution, resulting in damage behind the gypsum crust that protects the surface. Despite gypsum and halite not being the most aggressive salts, the porous nature of Crazannes limestone made it highly susceptible to salt-induced deterioration, leading to significant damage during storage, even with a minimal number of cycles. These results highlight the importance of controlling the storage conditions when stones are contaminated by salts.

Magnesia composite materials for layered products

The article presents the results of experimental studies of magnesia composite materials of layered structure obtained from molding mixtures of various densities. The aim of the work is to synthesize and study the characteristics of three–layer magnesia materials. Molding mixtures were obtained from combined binders based on caustic magnesite and technogenic silica-containing materials. Specially synthesized porous aggregates from liquid-glass raw mixtures were used as fillers. Technological techniques of horizontal and vertical molding of three-layer products have been worked out. Composite magnesia material of three-layer variatropic structure is characterized by a density of 560 kg/m3, compressive strength of 6.1 MPa. Durability tests of layered composite materials have been carried out. Three-layer magnesia composite materials have shown satisfactory resistance in the conditions of an aqueous and aggressive salt environment. The developed magnesia material is comparable in physic-mechanical and cost parameters with an innovative block of encapsulated expanded clay. The low thermal conductivity of the developed magnesia material, equal to 0.115 W/(m·⁰c), will ensure a reduction in material and energy costs by 36.1% compared to the cement analogue.

Corrosion behaviour of microstructurally modified elastic rail clip steel under crevice and aggressive salt fog exposure

In the present work, existing Indian elastic rail clip steel (tempered martensite) is microstructurally modified to bainite using austempering route. Crevice corrosion of elastic rail clip (ERC) is of major concern as metal dissolution can cause the loosening of the rail clip assembly (such as rail clipinsert and rail clipliner) and lack of performance. Furthermore, the surface of rail clip exposed to the atmosphere could also be affected by the corrosive environment. The present work concentrates on the findings of crevice corrosion and wetdry salt fog exposure of the austempered ERC steels in 3.5 wt% NaCl solution for 30 days and compared with the asreceived (existing) ERC steel which consists of tempered martensitic structure. The severity of corrosion has been investigated by studying the surface dissolution and the rust formed on the exposed surfaces of the ERC steels after the crevice and salt fog tests. Scanning electron microscopy (SEM) and optical profilometry have been used for the analysis of surface dissolution behaviour. Moreover, the rust formed on the exposed surfaces characterised using SEM shows the presence of various rust phases, such as αFeOOH, βFeOOH, γFeOOH, αFe2O3, etc. Furthermore, Raman spectroscopy has been used for the confirmation and quantification of these rust phases. The higher protective ability index (PAI) calculated from the quantitative assessment of different rust measured from Raman spectroscopy shows the better corrosion resistance of the austempered ERC stee

Hybrid Zinc Coatings with Chitosan/Alginate Encapsulated CuO-Nanoparticles for Anticorrosion and Antifouling Protection of Mild Steel

The construction of anticorrosion coatings containing antifouling agents is an effective way to ensure the long-term durability of marine steel infrastructures. In this work, an innovative hybrid coating was prepared by introducing biocide CuO nanoparticles in ordinary zinc coating to improve its protective ability for steel in aggressive salt water environments. The CuO nanoparticles were embedded inside the matrix of chitosan/alginate complexes to prevent spontaneous copper leaching during corrosive attacks. Two procedures were applied for the electrodeposition of hybrid/composite zinc-based coatings on low-carbon steel substrates (DC current): first—the co-electrodeposition of encapsulated CuO nanoparticles with zinc on a cathode (steel) electrode from a sulfate electrolyte with a relatively low pH value of about 4.5–5.0 and second—the encapsulated CuO nanoparticles were electrodeposited from aqueous solution as an intermediate layer between two zinc deposits. The particles size and stability of suspensions were evaluated using dynamic light scattering. Both hybrid coatings were compared in terms of surface morphology and hydrophilicity (SEM and AFM analysis, contact angle measurement) and corrosion resistance (potentiodynamic polarization curves, polarization resistance). The protective characteristics of the coatings were compared in a 3.5% NaCl solution and artificial sea water. The hybrid coating showed 2–4 times higher polarization resistance than the bare zinc coating during a 30 day immersion in artificial sea water, indicating that this coating has the necessary characteristics to be used in a marine environment.

Corrosion Behavior of a Newly Developed Moderately High C–High Si Multiphase Steel under Aggressive Salt Fog Exposure

Corrosion Behavior of a Newly Developed Moderately High C–High Si Multiphase Steel under Aggressive Salt Fog Exposure

Hybrid Zinc Coating with CuO Nanocontainers Containing Corrosion Inhibitor for Combined Protection of Mild Steel from Corrosion and Biofouling

In this study, a multifunctional hybrid coating is designed for the combined protection of mild steel from corrosion and biofouling in aggressive salt water. This involves preparation of a pH-responsive-release system based on copper oxide (CuO) as a biocide, and the corrosion inhibitor Safranin loaded in polymeric nanocontainers by alternate adsorption of poly(acrylic acid) and poly(ethylenimine) on CuO nanoparticles in water solutions. By optimizing the conditions, i.e., pH and concentration, good stability of the suspensions and the loading amount of Safranin is achieved. The nanocontainers are electrodeposited as an intermediate layer in an ordinary zinc coating on steel (“sandwich-like” structure) from the water solution in order to minimize the effect of CuO dissolution. To highlight the role of Safranin in reducing steel corrosion, a second zinc coating containing CuO nanoparticles without a corrosion inhibitor is also examined. The surface morphology and corrosion behavior of the hybrid coatings are evaluated in a model corrosion medium (5% NaCl solution). Both coatings are found to improve the anticorrosion behavior of steel for a time interval of 55 days and at conditions of external polarization. It can be expected that the newly developed hybrid coatings would also demonstrate potential for marine applications due to the main characteristics of their components.

Improvements in Hot Corrosion Behavior of CO2 Laser-Welded Fe-Based A-286 Alloy in an Aggressive Salt Environment by High-Velocity Oxy-Fuel Coating

Improvements in Hot Corrosion Behavior of CO2 Laser-Welded Fe-Based A-286 Alloy in an Aggressive Salt Environment by High-Velocity Oxy-Fuel Coating

Insights into the Crossover Effects in Cells with High‐Nickel Layered Oxide Cathodes and Silicon/Graphite Composite Anodes

AbstractSilicon anodes are regarded as one of the most promising alternatives to graphite (Gr) anodes due to their ultrahigh capacity, abundance, and low cost. Coupling Si‐based anodes with high‐nickel layered oxide cathodes LiNixMnyCo1−x−yO2 (NMC, x ≥ 0.8) can enhance the driving range for electric vehicles. Transition‐metal (TM) ion dissolution and deposition has been a long‐known failure mode for Gr‐based lithium‐ion batteries. However, the mechanistic insight associated with TM ion deposition on Si‐based anodes has rarely been reported. Herein, the impact of in situ deposited TM ions on SiOx/Gr composite anodes and the individual influences of Ni, Mn, and Co on the structural and electrochemical stability along with the underlying degradation mechanisms are presented. TM ion dissolution causes a greater deleterious impact on Si than on Gr, with different TM ions exhibiting different influences on anode‐electrolyte interphase formation. Specifically, Ni deposit induces more aggressive salt decomposition; Co deposit has negligible effect on salt decomposition, but significantly accelerates solvent decomposition; and Mn deposit aggravates both salt and solvent decompositions, resulting in worse full cell performance. The extent of degradation decreases in the order Mn2+ > Ni2+ > Co2+. The systematic comparisons presented can guide further development of high energy systems.

Hot corrosion behaviour of Inconel 738 superalloy in presence of NaCl, Na2SO4, V2O5

Superalloy are widely used for high temperature applications in diverse environment such as boilers, turbines and petrochemical industries for longer hours of operation. The application environment may have aggressive salts such as NaCl, Na2SO4, V2O5 which can catalase the hot corrosion thus affecting the normal working of the appliances. In present work, hot corrosion behavior of Inconel 738 superalloy studied by using cyclic hot corrosion test carried out at 700 °C for 10 cycles. For this study to know how the effect of salts on the alloy, each specimen was coated separately by NaCl, Na2SO4, V2O5 salt. After that, the coated specimens placed in the furnace. The cycle consists of 24Hr of heating at 700 °C in muffle furnace. Then, the specimens removed from the furnace and allowed to cool in the air environment. The weight gain after every cycle is measured and is used to determine the kinetics of hot corrosion. The graph of square of weight gain/Area Vs no of cycles was plotted. X-ray diffraction used to study the different types of oxides and compounds formed on the specimen surface. The morphology and electrochemical analysis of the specimens correlated to study the hot corrosion behavior. The rate constant (parabolic rate constant, KP) was determined from the weight gain data. The results showed that the specimen coated with Na2SO4 has lower corrosion as compare to the specimen coated with NaCl and V2O5 due to the presence of protective oxide such as Cr2O3, TiO2, Fe2O3, NiCr2O4, Ni3Ti formed on the specimen surface.

Processing, Adhesion and Corrosion-inhibiting Properties of Poly[2-methoxy-5-(2’-ethylhexyloxy)-1,4-phenylene vinylene], (MEH-PPV) on Aerospace Aluminum Alloys

Researchers at the Naval Air Warfare Center Weapons Division (NAWCWD) and Wright-Patterson Air Force Base (WPAFB) investigated poly[2-methoxy-5-(2’-ethylhexyloxy)-1,4-phenylene vinylene], (MEH-PPV) for its potential corrosion-inhibition properties on aerospace aluminum alloy AA2024-T3. Solution processing of the polymer, as well as adhesion testing and accelerated weathering tests were performed on MEH-PPV full military aerospace coatings. Wet and dry tape adhesion testing, as well as pencil hardness, impact flexibility and pneumatic adhesion tensile test instrument (PATTI) testing were used to demonstrate the adhesion performance of MEH-PPV on aluminum substrates. The results showed that MEH-PPV had acceptable adhesion characteristics when compared to hexavalent chromium (Cr(VI)) based coatings in all of these tests. Accelerated weathering analysis was performed on MEH-PPV coatings to determine their corrosion protection and weathering resistance capabilities. These tests included neutral salt spray (NSS) exposure and xenon-arc lamp testing. The results showed that while MEH-PPV does not exhibit significant color change after 500 hours of xenon arc lamp exposure, the polymer has poor corrosion protection performance under aggressive salt environments.

Observation of stress corrosion cracking using real-time in situ high-speed atomic force microscopy and correlative techniques

Contact-mode high-speed atomic force microscopy (HS-AFM) has been utilised to measure in situ stress corrosion cracking (SCC) with nanometre resolution on AISI Type 304 stainless steel in an aggressive salt solution. SCC is an important failure mode in many metal systems but has a complicated mechanism that makes failure difficult to predict. Prior to the in situ experiments, the contributions of microstructure, environment and stress to SCC were independently studied using HS-AFM. During SCC measurements, uplift of grain boundaries before cracking was observed, indicating a subsurface contribution to the cracking mechanism. Focussed ion beam milling revealed a network of intergranular cracks below the surface lined with a thin oxide, indicating that the SCC process is dominated by local stress at oxide-weakened boundaries. Subsequent analysis by atom probe tomography of a crack tip showed a layered oxide composition at the surface of the crack walls. Oxide formation is posited to be mechanistically linked to grain boundary uplift. This study shows how in situ HS-AFM observations in combination with complementary techniques can give important insights into the mechanisms of SCC.

Strength and Durability Properties of Concrete Containing Pumice and Scoria as Supplementary Cementitious Material

Concrete structures suffer serious deterioration under a corrosive environment. Consequently, the service life of these concrete structures is decreased and deteriorates under combined attack of sulphate and chlorides. Most studies confined on single deteriorating factor such as sulphate attack only or chloride attack only but the current study focused on the influence of natural pumice (NP) and natural scoria (NS) on the strength performance of concrete exposed to the combined attack of sulphate and chloride. Portland cement (PLC) was replaced with NP or NS at a substitution level of 10%. Concrete samples were cured in water for the curing period of 28 days. Afterwards, the specimens were immersed in 5% sodium sulphate (Na2SO4), 5% sodium chloride (NaCl), and combined sodium sulphate and chloride solutions for additional curing of 28, 56, and 90 days. The results were compared between concrete mixes with NP or NS and control mix (CT) with PLC. The effects of sulphate, chloride, and combined sulphate and chloride were evaluated in terms of change in weight, variation in compressive strength, and degree of damage. Conclusively, the application of NP and NS has extraordinary potential to be utilized as a cementitious material in concrete to increase the resistance against aggressive salts.

Improvement in hot corrosion resistance of dissimilar alloy 825 and AISI 321 CO2-laser weldment by HVOF coating in aggressive salt environment at 900°C

This study investigated the hot corrosion performance of a dissimilar weldment of Ni-based superalloy and stainless steel joined by CO2-laser welding and improved by high-velocity oxy-fuel (HVOF) coating in a Na2SO4-60wt%V2O5 environment at 900°C. A dissimilar butt joint of AISI 321 and alloy 825 was fabricated by CO2-laser welding with low heat input after obtaining the optimum welding parameters by bead-on-plate trials. The metallurgical and mechanical properties of the laser weldment were evaluated. The tensile test results indicated the occurrence of fracture in the base metal AISI 321 side. The HVOF process was employed to coat Ni-20wt%Cr on the weldment. To evaluate the surface morphology of the corrosion products formed on the uncoated and Ni-20wt%Cr-coated weldments, scanning electron microscopy (SEM) analysis was performed. Energy-dispersive spectroscopy (EDS) was used to determine the different elements present on the surface scales. The existence of oxide phases on the weldments was determined by X-ray diffraction (XRD). The cross sections of the weldments were characterized by SEM with EDS line mapping analysis. The results indicated that the Ni-20wt%Cr-coated weldment exhibited superior hot corrosion resistance due to the development of Cr2O3 and NiCr2O4 protective oxide scales.

Measurements and calculations of seasonal evaporation rate from bare sandstone surfaces: Implications for rock weathering

AbstractEvaporation from porous rock plays an important role in weathering processes. In the case of salt weathering, the evaporation rate controls supersaturation of salt solutions within pores and the amount of precipitated aggressive salts, therefore weathering occurs mostly in places with intense evaporation. Evaporation also strongly affects frost, hydric and biogenic weathering, as these are influenced by water content and its temporal changes. Despite its importance, evaporation from porous rocks has seen little scientific focus. We present a study on evaporation from bare sandstone, one of the most common rocks affected by weathering. A new method that measures the evaporation rate from the surfaces of sandstone samples under field microclimate was developed and tested. Also, a simple calculation of 1D evaporation rate from bare sandstone surfaces based on Fick's law of diffusion is presented. The measurement was performed using sandstone cores (with a set depth of the vaporization plane) in a humid continental climate and measured on a roughly monthly interval for about 1 year. For the calculations, a laboratory‐measured water‐vapour diffusion coefficient of the sandstone, in‐situ seasonally measured vaporization plane depth, and values of air humidity and temperature were used. The sensitivity analyses showed that the most important factor controlling the evaporation rate was the vaporization plane depth, while seasonal and spatial changes of air humidity and temperature were of lesser importance. The calculated evaporation rate reasonably follows measured values. For its simplicity and the small number of parameters required, the proposed method has the potential to improve knowledge of weathering and living conditions of endolithic and epilithic organisms. Further research should focus on factors affecting the evaporation rate (wind, hygroscopicity, hydrophobicity, etc.) to improve the accuracy of the calculations, as well as to test the applicability of the method for other lithologies and climates. © 2020 John Wiley & Sons, Ltd.

The influence of KCl on biomass ash melting behaviour and high-temperature corrosion of low-alloy steel

The main aim of this work was to determine the influence of KCl-rich ash deposits on 10CrMo9-10 steel oxidation rate. Two agricultural biomass samples: oat and rye straw, clean and doped with KCl were tested in this study. The addition of KCl does not decrease the melting temperature of the ash when KCl is not incorporated with mineral matter components.Corrosion experiments were performed at 550 °C and 600 °C, with corrosion coupons covered with real and synthetic biomass ash under oxidising conditions. The nonuniform distribution of KCl in ash affected the results and the effect of potassium concentration on oxidation rate was not observed in all cases. More severe influence of ash rich in KCl was observed at lower temperature, the reason is lower protective oxide scale formation rate and higher influence of ashes on steel material and scale.The temperature increase by 50 °C doubled the corrosion rate. At 550 °C KCl was most aggressive salt, but at 600 °C the influence of eutectic mixture KCl+K2SO4 was the highest. Even at lower temperature thermal decomposition of K2CO3 was observed affecting the results. It might be concluded that temperature and eutectic mixture formation are essential parameters in corrosion prediction.

In-situ phosphatization and enhanced corrosion properties of films made of phosphate functionalized nanoparticles

In the present work a thin, stand-alone waterborne coating with excellent anticorrosion performance was successfully designed thanks to a built-in ability to in-situ phosphatize low carbon steel substrates. During film formation, the phosphate functionalities, incorporated by using a phosphate functional surfmer, were able to interact with steel leading to a thin iron phosphate passive layer at the coating-metal interface, as proven by SEM-EDX, FTIR and XPS. The phosphatization layer that plays a key role on the excellent anticorrosion properties obtained (measured by EIS analysis of coated sample immersed in 3.5 wt% NaCl solution and in an aggressive salt spray chamber), strongly depends on the humidity at which the waterborne dispersion is applied; at relative humidity above 60%, optimum performance is achieved.

Coupled effect of relative humidity and temperature on the degradation of cement mortars partially exposed to sulfate attack

Abstract Concrete structures in salt lakes of western China and South China Sea deteriorate dramatically because of the aggressive salt, high temperature and low relative humidity (RH). In order to study the deterioration mechanism of cement-based materials in these severe environments, the damage progress of mortar specimens that partially exposed to sulfate solutions and under different ambient RH and temperatures was examined. The results indicate that the driving deterioration mechanism for cement mortars that partially exposed to Na2SO4 solution is physical attacks in drying portions, while it is chemical attacks in immersed portions for cement mortars that partially exposed to MgSO4 solution. Besides, lowering the ambient RH (e.g., from 80% to 50% and 30%) would promote a narrow but supersaturated evaporation interface zone, which accelerates the salt crystallization and eventually surface scaling. While the relatively high ambient RH (80%) causes a broad diffusion zone where the chemical related expansion and cracking formed. Moreover, an intermediate temperature of 35 °C is proved to produce the most severely deterioration when compared to the temperature of 20 and 50 °C.